Author Topic: Mechanical device required  (Read 1523 times)

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Offline truthseekerTopic starter

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Mechanical device required
« on: December 20, 2009, 01:20:17 PM »
I require two mechanical devices to facilitate the movement of a camera/camcorder on my electric wheelchair which will be controlled by a Basic Stamp(s) & a laptop. The first is a retractable pole in two pieces (the base: 5 feet- movable piece:4 feet). I am looking for a mechanical device like a ball screw to transfer horizontal movement to a vertical action. But I need the threaded piece to move instead of the ball. See drawing

The second apparatus, I assume a mixture of mechanical & electrical components powered by DC, is a device that can both move the camera in a horizontal & vertical way but not necessarily at the same time.
« Last Edit: December 20, 2009, 01:23:07 PM by truthseeker »

Offline little-c

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Re: Mechanical device required
« Reply #1 on: December 20, 2009, 02:58:37 PM »
for the second device, I'm assuming you want the camera to look left and right as well as up and down?

if so, two servos at 90 degrees to each other would work.
you want two degrees of freedom. one for each axis. any mechanical means of moving something in one axis, mounted perpendicular to another device capable of moving something in one axis would work. doesn't matter which way round you mount them. as long as they don't get in the way of each other.

for the first.

pulleys. and a 360 servo or a motor with good speed control and/or reduction gearbox and possibly a method of telling the hight of the pole.
you need a return system. springs, twin linked pulley motors, solenoids, electromagnets....  or just good old fashioned gravity ;)
 simply put you want to pull the rising structure up with a bit of string. and lower it gently using its own weight and controlling the release of string.

if you need more help on designing it, first I recommend getting out a bit of paper and a pencil. or a blackboard and chalk. (whiteboard.... though thats only in case of severe hardship)
still need more help, google some stuff on pulleys, etc. or how to raise and lower car aerials.

else ask back here.

hint, depending on what your using for materials depends on if you can get away with pin and spacer with washer guides, or need proper pulleys(boats, sailing boats...) and you can always run more than one of them.

Offline hopslink

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Re: Mechanical device required
« Reply #2 on: December 21, 2009, 03:31:27 AM »
The second device sounds like a readily available pan and tilt.

For the first, is there a particular reason why you cannot use a ballscrew in a standard manner?


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